APPENDIX I: Noise Monitoring Data - Xstrata Coal Mangoola
APPENDIX I: Noise Monitoring Data - Xstrata Coal Mangoola
APPENDIX I: Noise Monitoring Data - Xstrata Coal Mangoola
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1.3 Terminology<br />
Some definitions of terminology, which may be used in this report, are provided in Table 1.2.<br />
Table 1.2 TERMINOLOGY<br />
Descriptor<br />
L A<br />
L A10<br />
L A90<br />
L Aeq<br />
L pk<br />
dB(A)<br />
SPL<br />
SEL<br />
ABL<br />
RBL<br />
Hertz (Hz)<br />
Day<br />
Evening<br />
Night<br />
Definition<br />
The A-weighted root mean squared (RMS) noise level at any instant<br />
The noise level which is exceeded for 10 per cent of the time, which is<br />
approximately the average of the maximum noise levels<br />
The level exceeded for 90 per cent of the time, which is approximately the<br />
average of the minimum noise levels. The L A90 level is often referred to as the<br />
“background” noise level and is commonly used to determine noise criteria for<br />
assessment purposes<br />
The average noise energy during a measurement period<br />
The unweighted peak noise level at any instant<br />
<strong>Noise</strong> level measurement units are decibels (dB). The “A” weighting scale is<br />
used to describe human response to noise<br />
Sound pressure level (SPL), fluctuations in pressure measured as 10 times a<br />
logarithmic scale, the reference pressure being 20 micropascals<br />
Sound exposure level (SEL), the A-weighted noise energy during a<br />
measurement period normalised to one second<br />
Assessment background level (ABL), the 10th percentile background noise<br />
level for a single period (day, evening or night) of a 24 hour monitoring period<br />
Rating background level (RBL), the background noise level for a period (day,<br />
evening or night) determined from ABL data<br />
Cycles per second, the frequency of fluctuations in pressure, sound is usually a<br />
combination of many frequencies together<br />
The period 7:00am to 6:00pm<br />
The period 6:00pm to 10:00pm<br />
The period 10:00pm to 7:00am<br />
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